1. Field of the Invention
The present invention relates generally to an electrotherapy device. Specifically, the present invention relates to an electrotherapy device that is manually powered. More specifically, the present invention relates to a battery-less, human-powered electrotherapy device and method of use. Electrotherapy devices include defibrillators, cardioverters and training devices that simulate the operation of an electrotherapy device. Defibrillators include automatic or semi-automatic external defibrillators (AEDs); including those defibrillator that deliver monophasic, biphasic or multiphasic waveforms externally to a patient.
2. Description of the Prior Art
Electrotherapy devices are used to provide electric shocks to treat patients for a variety of heart arrhythmias. For example, external defibrillators typically provide relatively high-energy shocks to a patient (as compared to implantable defibrillators), usually through electrodes attached to the patient""s torso. External defibrillators are used to convert ventricular fibrillation (xe2x80x9cVFxe2x80x9d) or shockable ventricular tachycardia (xe2x80x9cVTxe2x80x9d) to a normal sinus rhythm. Similarly, external cardioverters can be used to provide paced shocks to convert atrial fibrillation (xe2x80x9cAFxe2x80x9d) to a more normal heart rhythm.
Sudden cardiac arrest (xe2x80x9cSCAxe2x80x9d) is the leading cause of unanticipated death in the United States. On average, about 600 people per day die of SCA. This translates to nearly one death every two minutes. It is likely that these statistics would hold true for third world countries. Precise international statistics are not available but the U.S. rate for coronary heart disease deaths, of which sudden deaths constitute nearly half, is representative of international rates (rank 16th and 13th among 36 nations reported by the World Health Organization (WHO), for men and women, respectively).
Most sudden cardiac death is caused by VF, in which the heart""s muscle fibers contract without coordination, thereby interrupting normal blood flow to the body. The only effective treatment for VF is electrical defibrillation, which applies an electrical shock to the patient""s heart. The electrical shock clears the heart of the abnormal electrical activity (in a process called xe2x80x9cdefibrillationxe2x80x9d) by depolarizing a critical mass of myocardial cells to allow spontaneous organized myocardial depolarization to resume.
To be effective, the defibrillation shock must be delivered to the patient within minutes of the onset of VF. Studies have shown that defibrillation shocks delivered within one minute after the onset of VF achieve up to a 100% survival rate. However, the survival rate falls to approximately 30% after only 6 minutes. Beyond 12 minutes, the survival rate approaches zero. Importantly, the more time that passes, the longer the brain is deprived of oxygen and the more likely that brain damage will result. As improved access to defibrillators increases, survival rates from SCA also increase.
The electrical pulse must be delivered within a short time after onset of VF in order for the patient to have any reasonable chance of survival. To be effective, the defibrillation shock must be delivered to the patient within minutes of the onset of VF. Studies have shown that defibrillation shocks delivered within one minute after the onset of VF achieve up to a 100% survival rate. However, the survival rate falls to approximately 30% after only 6 minutes. Beyond 12 minutes, the survival rate approaches zero. Importantly, the more time that passes, the longer the brain is deprived of oxygen and the more likely that brain damage will result. Electrical fibrillation may also be used to treat shockable ventricular tachycardia (xe2x80x9cVTxe2x80x9d). Accordingly, defibrillation is the appropriate therapy for any shockable rhythm, that is, VF or shockable VT.
One way of providing electrical defibrillation uses implantable defibrillators, which are surgically implanted in patients that have a high likelihood of experiencing VF. Implanted defibrillators typically monitor the patient""s heart activity and automatically supply the requisite electrical defibrillation pulses to terminate VF. Implantable defibrillators are expensive, and are used in only a small fraction of the total population at risk for sudden cardiac death.
External defibrillators send electrical pulses to a patient""s heart through electrodes applied to the patient""s torso. External defibrillators are typically located and used in hospital emergency rooms, operating rooms, and emergency medical vehicles. Of the wide variety of external defibrillators currently available, automatic and semi-automatic external defibrillators, collectively referred to as xe2x80x9cAEDsxe2x80x9d, are becoming increasingly popular because relatively inexperienced personnel can use them. U.S. Pat. No. 5,607,454 to Cameron et al., entitled Electrotherapy Method and Apparatus, and PCT publication number WO 94/27674, entitled Defibrillator With Self-Test Features, the specifications of which are hereby incorporated by reference, describe AEDs.
AEDs provide a number of advantages, including the availability of external defibrillation at locations where external defibrillation is not regularly expected, and is likely to be performed quite infrequently, such as in residences, public buildings, businesses, personal vehicles, public transportation vehicles, among other locations
A big problem with deploying a device, such as a defibrillator, in a remote location is the need to ensure a reliable power supply. Because of the cost, disposable batteries are not a practical solution. Additionally, because of the lack of an AC or DC power supply generally, rechargeable batteries are also not a practical solution. What is needed, therefore, is a device that is capable of monitoring a patient and defibrillating the patient""s heart, if necessary, but which can be powered manually.
The present invention provides an electrotherapy device including a human powered power supply. An energy delivery system is operably connected to the power supply for delivering an electric energy to a patient. A controller is operably connected to the energy delivery system for controlling the energy delivery system.
The present invention also provides a method for operating a defibrillator. A human powered power supply is operated. It is determined whether a patient has a shockable rhythm. A defibrillating shock is administered to the patient through an energy delivery system operably connected to the human powered power supply if the patient has a shockable rhythm
Still other objects and advantages of the present invention will become readily apparent by those skilled in the art from a review of the following detailed description. The detailed description shows and describes preferred embodiments of the invention, simply by way of illustration of the best mode contemplated of carrying out the present invention. As will be realized, the invention is capable of other and different embodiments and its several details are capable of modifications in various obvious respects, without departing from the invention. Accordingly, the drawings and description are illustrative in nature and not restrictive.